osu!catch, formerly known as Catch the Beat or CtB, is a game mode that requires the player to control a character(catcher) who catches falling fruit in tune to the beat.

Gameplay

Song Selection

To access the osu!catch game mode, press Ctrl+3 at the same time.

Alternatively, click on the Mode button and select osu!catch.

Gameplay Basics

Playfield

osu!catch playfield difference based on CS

Left is CS2 playfield and right is CS7 playfield

The zoom size of the playfield is based on CS (Circle Size) settings, with lower CS means much more zoomed in and smaller space, while higher CS means much more zoomed out and larger movement space.

The catcher can move from left to right, with the fruits falling from top to bottom.
The catcher cannot move pass the left and right walls of the playfield.

All fruits will stay at the plate until its combo ends, which the fruits will bounce out of the plate.
Timing and where it falls on the plate does not matter; either a full score for successful catch or miss.

Fruits

osu!catch fruits

Fruits are the hit circles of osu!catch, and it rains down from top of the screen

To catch these fruits, make sure it falls to the plate and not over the plate.
Collected fruits will always give 300 points each, increment combo by 1, and treated as 300 in result screen.

Fruit trails

osu!catch fruit trails

Fruit trails are the sliders of osu!catch

A typical fruit trail will contains two fruits (start and end), droplets (slider path), juice drop (slider ticks), and more fruits for each reverse arrow points along with a reversed slider path.
Droplet gives 10 points each and treated as 50 in result screen.
Juice drop gives 30 points each, increment combo by 1, and treated as 100 in result screen.

Missing the juice drop will break the combo (as it is a slider tick), but missing the droplet will not break the combo.
However, missed droplets will not be shown in the local result screen, but will be shown in the website's leaderboard as Miss Droplet, which notably affects accuracy (missed out the droplet, which is a 50) and score (10 points for each droplet missed).

Bananas

osu!catch bananas

Bananas serves as spinners in osu!catch.

Here, large bananas will rain down and shrink down to catch size as it falls down to the plate (or not).
Each collected bananas will give a static score of 1,100 regardless of mod and combo multiplier.

The bananas can be ignored with no health penalty.
However, it can cost the extra points and health recovery from collecting the bananas.
Notably, Auto mod will go above and beyond to catch all of the bananas without fail.

Hyperfruits

osu!catch hyperfruits

Left: Before collecting the hyperfruit. Right: Catcher hyperdash to the next fruit and leaving an afterimage.

Hyperfruits are special fruits that will appear to help the catcher to catch the next fruit when normal dash is considered impossible to catch it in a strict timespan allocated.
All hyperfruits have a signature red colour surrounding the hyperfruit itself by default.

Collecting the hyperfruit will make the catcher's dash upgraded to hyperdash (just fast enough to catch the next fruit), glows red, and leaves a temporary red afterimage at the collection point, until the next one fruit was caught or dropped, which the catcher will then be back to normal.

Controls

Catcher control

By default, the left <-(L) and right ->(R) arrow keys to move the catcher.

Press and hold the leftShift(D) key with one of the arrow keys will make the catcher dash in that direction at x2.0 speed (indicated with a bright glow from the catcher).

Alternatively, press and hold the Left Click(D) button on the mouse to trigger the dash.

The placement of in-game cursor does not matter when playing normally.
If Relax mod was enabled, the control of the catcher will be the in-game cursor instead.
However, the play unrankable when Relax mod was enabled (as it defeats the only challenge of osu!catch; fixed catcher speed and catcher plate control).

Note: There is a difference between osu!standard and osu!catch's scoring methods:-

300s and a combo increment are not given to a finished spinner

reverse slider ticks are counted as a full score of a hit

note that in osu!standard, a reverse tick only gives 30 points

Hit objects judgement

All except bananas

Full score when collected.

Miss when failed.

Bananas

Constant score of 1,100 per banana collected.

Nothing happens for missed bananas.

Score/Combo Multiplier

The following each add a point to the score/combo multiplier:-

Collecting the fruits.

Collecting the juice drops.

The following will reset the score multiplier to zero:-

Missed the fruits.

Missed the juice drops.

The following will not increase or reset the score multiplier:-

Collecting the droplets.

Collecting the bananas.

Health bar

The system used to calculate health drain and health gain is complicated so it will not be explained in detail.
It all revolves around the HP difficulty setting which can only be set by the mapper itself.

History

Catch the Beat logo in Special Mode

osu!catch (Catch the Beat) logo in deprecated Special Mode

Until 10 April 2012 (2012-04-10), osu!catch maps could not be ranked or be included in ranked maps.
However, this has now changed, and mappers may now make osu!catch-specific difficulties, provided they follow the guidelines.
These guidelines are very much a work in progress, but as more osu!catch maps are ranked and feedback is given from their players, the guidelines will evolve to be as thorough and comprehensive as the osu!standard guidelines.